1997 Sport Nautique Red Warning light

[scubaguyjohn]

The red warning light (for water temp and oil pressure) doesn't come on when the ignition key is turned to the "on" position. When I add ground to the temp sensor or oil pressure wires, the light does come on so I know those wires aren't the issue.

What provides ground to the (green) wire when the key is in the "on" position?

The light worked last year with the exact same wiring set-up so I have no idea what changed.

FYI, I added a back-up alarm to the light circuit to give me an audible warning should the light get triggered as the red light is impossible to see when you're driving in sunlight.

thanks, John.

[scubaguyjohn]

anyone have an idea?

[flipflop]

Is this on a GT-40?

I wish there was a diagram around for dash wiring on 90s sport/and super sports.

[pSchwade]

your backup alarm might be drawing too much current - try it without the audible alarm. it could also be inadequate grounding to the light (I had to re-wire the entire dash power supply in my '99 to fix a bunch of small intermittent problems that were caused by poor wiring)

[scubaguyjohn]

thanks...the alarm is definitely not drawing too much power as this exact same set-up worked last year. Also, the light won't turn on with the ignition in the "on" position even without the alarm attached to the circuit.

There has to be a connection/device that provides a momentary ground to that circuit when the ignition is in the "on" position and then disconnects when the engine starts. Temporarily grounding the oil pressure sensor and the water temp sensors does correctly trigger the alarm/light so the only issue is when the key is turned on without turning it all the way to the engine run position.

I've read elsewhere that a diode of sorts is used to provide the tempeorary ground but can't find anything by tracing wires. I do believe the issue is an intermittant/bad connection because every once and while the alarm/light do work with the key in the "on" position.